Cooling device for the heads of furnaces



y 1933- F. FIORELLI COOLING DEVICE FOR THE HEADS OF FURNACES Filed Sept. 26, 1931 Patented May 2, 1933 FFICE PATENT FERDINANDO FIORELLT, OF TERNI, ITALY, ASSIGNOR TO TERNI SOCIEIA PER LINDUSTRIA E LELETTRIGITA, OF HOME, ITALY, A CORPORATION OF ITALY COOLING DEVICE FOR THE HEADS OF FURNACES Application filed September 26, 1931, Serial No. 565,348, and in Italy June 20, 1931.

This invention relates to a method of and a cooling device for the furnace heads of Siemens-Martin and the like furnaces.

The object of cooling devices is to increase the life of furnace head parts made of refractory material, to avoid stoppages on account ,of repairs to these parts and to ensure good conditions of combustion by maintaining the cross-sections of the air and gas flues.

The known cooling devices fail however to fulfill this object in a satisfactory manner as in all of them the thermic efficiency of the furnace is considerably reduced.

The present invention provides a cooling method which is free from the disadvantages of the known devices. The process according to this invention consists in mixing with the escaping hot combustion gases, before they pass into the furnace head, cold inert gases which bring about such areduction of temperature of the escaping gases as to reduce or entirely to eliminate their destructive effect on the masonry of the furnace heads.

According to the present invention, the escaping flame is cooled by a cold current of an inert or neutral gas which is injected into the furnace chamber, that is to say, before the flame strikes the front surface of the furnace head. This produces a kind of protective cushion between the points of the flames and the masonry.

The two gas currents, that is to say, the current injected with the outside temperature into the interior of the furnace and the current of the escaping combustion gases which are to be cooled, meet together in the mixing chamber of the discharge head and become there thoroughly mixed until thermic equilibrium is produced. Owing to the considerablereduction of temperature of the flame, the life of the furnag e heads exposed to alternate stresses, is substantailly increased.

By inert gases are meant nitrogen and other incombustible gases as well as mixtures of such gases, for instance products of combustion in general.

As an example for carrying out the invention, the accompanying drawing shows diagrammatically a construction for a Siemens- Martin furnace.

Figure 1 shows an arrangement for carrylng out the process, in longitudinal section, and

Figure 2 in plan.

Figure 3 is a view looking towards the furnace head.

H is the furnace chamber. Air is supplied to the mixing chamber in the known manner through the flue L, and the gas through the flue G. The mixture of air and gas formed in the mixing chamber is burnt in the furnace chamber H.

According to the invention, in the masonry partition separating the air flue L from the gas flue G, are provided a number of ducts a which open at the front wall of the masonry partition or bridge, and through which is injected an inert gas. Moreover, in the furnace masonry further ducts b may be provided, which open in direct proximity to the point where the escaping hot gases pass from the furnace chamber H into the mixing chamber M, and through which are also injected inert gases. These gases produce the above mentioned cooling action.

The ducts a and b are connected by pipes a and b to a joint pipe 0. In order to supply in certain cases the inert gases only to the escaping head, there are naturally provided closing members which are connected together and may be also coupled to the reversing members of the furnace. As the above mentioned ducts are provided in the same way also in the other head (not shown) of the Siemens-Martin furnace, the changing-over of gas and air for the furnace working by this coupling will change also the direction of supply of the inert gases. The quantity of the cooling gas introduced into the individual ducts is preferably regulated by means of dampers or valves.

Having now particularly described and as certained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. A method of cooling furnace heads of Siemens-Martin and like furnaces consisting in mixing cold inert gases with the escaping hot combustion gases before they pass into the furnace head to produce such a reduction of temperature of the escaping gases as to substantially eliminate their destructive action on the masonry of furnace heads.

2. A method of cooling furnace heads of Siemens-Martin and like furnaces consisting in introducing cold inert gases into the mix- 7 ing chamber between the points of introduction of the main gas and air supplies, and

also introducing cold inert gases into the es- Gaping hot gases at the exit end of a mixing chamber and before the passage of the mixture into the furnace head to produce such a reduction of temperature of the escaping gases as to substantially eliminate their destructive action 011 the masonry of furnace heads.

3. Apparatus for cooling Siemens-Martin and like furnaces comprising in combination a furnace chamber, a furnace head rovided with a mixing chamber communicating with the furnace chamber and also provided with a partition dividing the head into two passages through which air and gas is admitted to the mixing chamber, means for introducing cold inert gas at the head of the mixing chamber and between the passages supplying the main supply of air and gas, channels provided in the head and communicating with the interior thereof adjacent the exit end of'the mixing chamber, and means for supplying cold inert gases through said channels so that the cold inert gases mix with the escaping hot gases before they pass into the furnace chamber to produce such a reduction of temperature of escaping gases as to substantially eliminate their destructive action on the parts.

In testimony whereof I have hereunto signed my name.

FERDINANDO FIORELLI 

